GBC CombBind Standard Spines, 3/8" Diameter, 60 Sheet Capacity, Black, 100/Box

Communicate your ideas with professional polish. 19-ring plastic spines won't scratch, chip, peel or discolor. Perfect for internal reports and functional documents. Bind 11 x 8 1/2 documents. Editing capability with a machine. Compatible with GBC and other plastic comb binding machines. To select correct diameter, measure thickness of material (including covers) and add 1/8".